Im planning out my next motor build and Im wondering, what is actually needed for a nitrous motor? Im looking at some engine packages and they seem too expensive for what they are.

If I was to build a nitrous motor (Vortec 4.3) What would be needed to change to make it handle some nitrous. Forged Pistons/Rods, performance bearing set, ARP studs and bolts throughout and properly set up rings for nitrous. Those are the things I can think of to change a normal rebuild into a fairly stout nitrous motor. Im not talking 400 shot or anything, prolly max 175.

.030 over 4.3
JE 4.030 Extreme duty pistons
5.7 Eagle H beam Rods(block needs clearancing for rods?)
266R Comp Cam
Stock oil pump/pickup
Stock DamperFlexplate/Timing Chain
ARP studs/bolts
Clevite Bearings
Ported stock Vortec heads w/3 angle valve job


Am I on the right track here? Do I have my thoughts of nitrous motor wrong?

 

you have the right idea and just have the rings gapped properly for the amount of spray planned.

 

I'd mill the heads a bit and bump the compression a bit too, you'd be suprised how much different a. 100 shot feels at say 10:1 rather than 9:1... Just for an example.

Or of you don't want to mill, just get the proper piston for the CR you want.... I'd shoot for 10.3-10.5 for a street motor if you're not planning over a 200 hit.

 

The biggest difference for nitrous is always the forged pistons. You can get away with hypertechnic pistons on a hot street motor, but any built nitrous motor should have forged. Also on a SBC we ran about 20-25 thousandths on the gaps for nitrous, but I don't know if the new series changed this. Also total gap is determined by total nitrous HP to some extent. I always liked big gaps to help the rings live, but it will burn a bit of oil on the street.

Any quality fastener "stock or ARP" will work for under a 250 shot, but when you go above that you need to really look at ARP studs and a girdle or stronger main caps.

Try a staged nitrous system or use a timer to ramp up a healthy single shot. They are incredable.

 

I sprayed a 125 shot on a stock 4.3 and that same motor has 150k miles on it right now. Timing was never backed down or anything. I wouldn't go too crazy with forged stuff and what not because IMO you won't spray the 4.3 long before you say what the hell time for a motor swap. I would spray the house down on what you have and if it pops before you are ready to swap motors toss another one in. I use the same logic I used on my motorcycles, how much money are you willing to throw at a 600cc bike to beat a 1000. It can be done but why not start with the better platform?

 

i was told that you could buy the kits for the small block 350s cheaper then the kits for the 4.3 and have two pistions and rods leftover for extras, if you are looking at the price for kits. i dont know if this is true.

 

when you go 200+ shot you need a cam that is setup for nitrous
when you are below that you just build it like a n/a setup and just have the n2o on top of that

 

Where was 200 shot mentioned. He said 175 max.

Be sure to remember this is a 6 banger....

 

Nitrous cams are a marketing ploy to make spray addicts sleep better at night.